Problem: On the way to school, Karen became fixated on the puzzle game on her phone!

<image>

The game is played as follows. In each level, you have a grid with n rows and m columns. Each cell originally contains the number 0.

One move consists of choosing one row or column, and adding 1 to all of the cells in that row or column.

To win the level, after all the moves, the number in the cell at the i-th row and j-th column should be equal to gi, j.

Karen is stuck on one level, and wants to know a way to beat this level using the minimum number of moves. Please, help her with this task!

Input

The first line of input contains two integers, n and m (1 ≤ n, m ≤ 100), the number of rows and the number of columns in the grid, respectively.

The next n lines each contain m integers. In particular, the j-th integer in the i-th of these rows contains gi, j (0 ≤ gi, j ≤ 500).

Output

If there is an error and it is actually not possible to beat the level, output a single integer -1.

Otherwise, on the first line, output a single integer k, the minimum number of moves necessary to beat the level.

The next k lines should each contain one of the following, describing the moves in the order they must be done:

  * row x, (1 ≤ x ≤ n) describing a move of the form "choose the x-th row". 
  * col x, (1 ≤ x ≤ m) describing a move of the form "choose the x-th column". 



If there are multiple optimal solutions, output any one of them.

Examples

Input

3 5
2 2 2 3 2
0 0 0 1 0
1 1 1 2 1


Output

4
row 1
row 1
col 4
row 3


Input

3 3
0 0 0
0 1 0
0 0 0


Output

-1


Input

3 3
1 1 1
1 1 1
1 1 1


Output

3
row 1
row 2
row 3

Note

In the first test case, Karen has a grid with 3 rows and 5 columns. She can perform the following 4 moves to beat the level:

<image>

In the second test case, Karen has a grid with 3 rows and 3 columns. It is clear that it is impossible to beat the level; performing any move will create three 1s on the grid, but it is required to only have one 1 in the center.

In the third test case, Karen has a grid with 3 rows and 3 columns. She can perform the following 3 moves to beat the level:

<image>

Note that this is not the only solution; another solution, among others, is col 1, col 2, col 3.

Solution (in JAVA):

Solution:
import java.io.*;
import java.math.BigInteger;
import java.util.*;
 

public class Main{
	public static final int mod = 1000000007;
	public static String ans ;
	public static int c;
	public static void main(String[] args)throws IOException {
		// TODO Auto-generated method stub
		InputStream input = System.in;
		Reader in  = new Reader();
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	
		int n = in.nextInt();
		int m = in.nextInt();
		
		int a[][] = new int[n][m];
		
		for(int i=0; i<n; i++)
			for(int j=0; j<m; j++)
				a[i][j] = in.nextInt();
		
		int lim = 501;
		for(int j=0; j<m; j++)
			lim = Math.min(lim, a[0][j]);
		
		int mink = -1,minc = Integer.MAX_VALUE;
		for(int i=0; i<=lim; i++)
			if(valid(a,n,m,i,0))
			{
				
				if(minc > c)
				{
					mink = i;
					minc = c;
					
				}
				
				
			}
		
		if(mink == -1)
			System.out.println("-1");
		else
		{
			valid(a,n,m,mink,1);
			System.out.println(c);
			System.out.println(ans);
		}
	}
	
	static boolean valid(int a[][],int n,int m,int k,int typ)
	{
		
		
		int row[] = new int[n];
		int col[] = new int[m];
		row[0] = k;
		c = k;
		for(int j=0; j<m; j++)
		{
			col[j] = Math.max(0,a[0][j] - row[0]);
			c += col[j];
		}
		
		for(int i=1; i<n; i++)
		{
			row[i] = Math.max(0,a[i][0] - col[0]);
			c += row[i];
		}
		
		for(int i=0; i<n; i++)
			for(int j=0; j<m; j++)
				if(a[i][j] != row[i] + col[j])
					return false;
		
		if(typ == 0)
			return true;
		
		StringBuilder sb = new StringBuilder("");
		c = 0;
		for(int i=0; i<n; i++)
		{
				c += row[i];
				for(int j=1; j<=row[i]; j++)
					sb.append("row "+(i+1)+"\n");
		}
		
		for(int i=0; i<m; i++)
		{
			c += col[i];
			for(int j=1; j<=col[i]; j++)
				sb.append("col "+(i+1)+"\n");
		}
		
		ans = sb.toString();
		return true;
	}
	
static int gcd(int a,int b)
{
	if(b == 0)
		return a;
	else return gcd(b,a%b);
}
static int lcm(int a, int b)
{
	
	return (a*b)/gcd(a,b);
}
	 static class Reader
	    {
	        final private int BUFFER_SIZE = 1 << 16;
	        private DataInputStream din;
	        private byte[] buffer;
	        private int bufferPointer, bytesRead;
	 
	        public Reader()
	        {
	            din = new DataInputStream(System.in);
	            buffer = new byte[BUFFER_SIZE];
	            bufferPointer = bytesRead = 0;
	        }
	 
	        public Reader(String file_name) throws IOException
	        {
	            din = new DataInputStream(new FileInputStream(file_name));
	            buffer = new byte[BUFFER_SIZE];
	            bufferPointer = bytesRead = 0;
	        }
	 
	        public String readLine() throws IOException
	        {
	            byte[] buf = new byte[64]; // line length
	            int cnt = 0, c;
	            while ((c = read()) != -1)
	            {
	                if (c == '\n')
	                    break;
	                buf[cnt++] = (byte) c;
	            }
	            return new String(buf, 0, cnt);
	        }
	 
	        public int nextInt() throws IOException
	        {
	            int ret = 0;
	            byte c = read();
	            while (c <= ' ')
	                c = read();
	            boolean neg = (c == '-');
	            if (neg)
	                c = read();
	            do
	            {
	                ret = ret * 10 + c - '0';
	            }  while ((c = read()) >= '0' && c <= '9');
	 
	            if (neg)
	                return -ret;
	            return ret;
	        }
	 
	        public long nextLong() throws IOException
	        {
	            long ret = 0;
	            byte c = read();
	            while (c <= ' ')
	                c = read();
	            boolean neg = (c == '-');
	            if (neg)
	                c = read();
	            do {
	                ret = ret * 10 + c - '0';
	            }
	            while ((c = read()) >= '0' && c <= '9');
	            if (neg)
	                return -ret;
	            return ret;
	        }
	 
	        public double nextDouble() throws IOException
	        {
	            double ret = 0, div = 1;
	            byte c = read();
	            while (c <= ' ')
	                c = read();
	            boolean neg = (c == '-');
	            if (neg)
	                c = read();
	 
	            do {
	                ret = ret * 10 + c - '0';
	            }
	            while ((c = read()) >= '0' && c <= '9');
	 
	            if (c == '.')
	            {
	                while ((c = read()) >= '0' && c <= '9')
	                {
	                    ret += (c - '0') / (div *= 10);
	                }
	            }
	 
	            if (neg)
	                return -ret;
	            return ret;
	        }
	 
	        private void fillBuffer() throws IOException
	        {
	            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
	            if (bytesRead == -1)
	                buffer[0] = -1;
	        }
	 
	        private byte read() throws IOException
	        {
	            if (bufferPointer == bytesRead)
	                fillBuffer();
	            return buffer[bufferPointer++];
	        }
	 
	        public void close() throws IOException
	        {
	            if (din == null)
	                return;
	            din.close();
	        }
	    }
}